(a) Field of the Invention
The present invention relates to a handheld clamping tool and more particularly, to a simple design of handheld clamping tool, which uses a driving handle with an integrated cam portion for driving actuation plates and a release bar for releasing the reserved energy.
(b) Description of the Prior Art
Many clamping tools are known. U.S. Pat. No. 7,513,492 discloses a clamping tool, entitled “hand held quick-clamping device” and issued to the present inventor. This design of hand held quick-clamping device includes an adjusting rod, a retaining handle, a driving handle, a first clamping block, and a second clamping block. The adjusting rod intersects the retaining handle, a set of adjusting sheets, and the stop sheets. A first clamping block is locked in a predetermined end of an adjusting rod, and a second clamping block is formed on a top end of the retaining handle. A driving handle is pivoted to the retaining handle. A traveling top shaft is installed in the retaining handle, and an axial shaft is opposite to it. While the driving handle is pressed, a top end of the driving handle pushes the top shaft. Through the top shaft, the axial shaft pushes the adjusting sheets and the stop sheets. And the movement of the sheets will drive an adjusting rod to move in one direction, thus producing a clamping or extending function. This design of clamping tool is functional, however, it uses a large number of component parts, increasing the cost and complicating the installation. There is room for improvement.
Further, the holes of the adjusting sheets and stop sheets for the coupling of the adjusting rod are I-shaped holes. The adjusting rod may be moved up and down in the holes of the adjusting sheets and stop sheets, leading to false action and affecting normal clamping (or expanding) function.